spark plugs heat range

[Nacho-RT74]

Would wish to know about that, and how to make a propper selection on an engine.

[firefighter3931]

Would wish to know about that, and how to make a propper selection on an engine.

The correct heat range is largely dependant on the compression ratio. On iron head BB mopars running pump gas i like the NGK XR5 plugs. 


Ron

[charger2fast4u]

Would wish to know about that, and how to make a propper selection on an engine.

The correct heat range is largely dependant on the compression ratio. On iron head BB mopars running pump gas i like the NGK XR5 plugs. 


Ron

so for a close to stock built 440 iron headed motor NGK XR5  plugs would be good to use? also what gap would be suitable .035? and what if you have a mopar performance electronic ignition upgrade would it be the same gap size?

[firefighter3931]

Would wish to know about that, and how to make a propper selection on an engine.

The correct heat range is largely dependant on the compression ratio. On iron head BB mopars running pump gas i like the NGK XR5 plugs. 


Ron

so for a close to stock built 440 iron headed motor NGK XR5  plugs would be good to use? also what gap would be suitable .035? and what if you have a mopar performance electronic ignition upgrade would it be the same gap size?

Sure, the XR5's are fine for that application. With the MP electronic ignition upgrade you are fine at .035-.040 gap 


Ron